nah, negotiator is easy if you CC the adds, they are the ones that provide the % based attack. lightning and discharge them, and you should be fine for a while, and when in doubt, kite, because the adds need to be in range to cast % based attack. there is a weird mechanic in that fight were many regular silence/slows have a knockdown effect on the adds, and as scout, i just pop all the adds with joint blow every now and then and it's fine, because the adds can't cast the spell while face up on the ground. idk what skills from m/p work for the knockdown, but test a couple of the standard CC skills i have mentioned and you should figure it out.
also, if you can't figure out how to CC the adds, then just t-storm kite adds/boss, and you will beat him unscathed, even though it may take a while
cheers and gl
edit: with that HP and MATT, you should be able to solo TT if you so desired...may take a bit of time due to low attack, but would be possible...i used to be able to solo TT on my scout with lower stats than that, and yes, ik scouts are different than mages, but honestly, from playing both, m/p has more solo ability than s/d anyday